Detergent composition with suds suppressing system

ABSTRACT

Detergent compositions are described which comprise a suds suppressing system consisting of a mixture of a silicone oil and a 2-alkyl-alcanol, or mixtures thereof.

TECHNICAL FIELD

The present invention relates to a suds suppressing system for detergentcompositions.

BACKGROUND

The modern conditions of laundry washing, especially in Europeancountries, involve important mechanical agitation in the washing machinethereby promoting the formation of suds in the washing process. It istherefore an essential aspect of modern laundry detergent compositionsthat they should comprise an efficient suds control system, oftenreferred to also as suds suppressing system.

It is well known in the art that various silicone oils can provideeffective suds control, and many prior art documents therefore discloseliquid detergent compositions comprising silicone oils. See for instanceU.S. Pat. Nos. 4,798,679, 4,075,118 and EP 150 872.

However, silicone oils suffer a certain number of drawbacks. A majordrawback is that the incorporation of silicone oils in liquid detergentsmay raise physical stability issues as the level of silicone oil israised. This problem is particularly acute as detergent compositions areformulated which are more concentrated, which is currently the trend inthis technical field.

Also, silicone oils are specialty chemicals which are quite expensive.It is therefore an object of the present invention to formulatedetergent compositions which have an efficient suds suppressing system,wherein said suds suppressing system comprises a minimal amount ofsilicone oil.

It has now been found that this object can be met by using a sudssuppressing system which comprises a mixture of a silicone oil and a2-alkyl-alcanol.

2-alkyl-alcanols have been described in DE 40 21 265 as suds suppressorsin detergent compositions. The present invention is based on the findingthat silicone oils and 2-alkyl-alcanols will act in synergy to controlsuds. This finding allows to formulate detergent compositions whichcomprise very low levels of silicone oils. In some instances, it hasbeen found that the level of both the silicone oil and the2-alkyl-alcanol can be reduced by a factor three in a mixed suds controlsystem according to the present invention, compared to the level neededto achieve the same suds control with either ingredient alone.

SUMMARY OF THE INVENTION

The present invention is a detergent composition comprising a surfactantsystem and a suds suppressing system, characterized in that said sudssuppressing system comprises from 0.06% to 12% of a mixture of asilicone oil, or mixtures thereof, with a 2-alkyl-alcanol, or mixturesthereof.

DETAILED DESCRIPTION OF THE INVENTION

The detergent compositions according to the present invention comprise asurfactant system and a suds suppressing system. The surfactant systemcomprises one or more surfactants.

The detergent compositions herein comprises from 5% to 60% by weight ofthe total detergent composition, preferably from 20% by weight to 40% byweight of a surfactant system. Suitable surfactants for use hereininclude organic surface-active agent selected from nonionic, anionic,cationic and zwitterionic surface-active agents and mixtures thereof.

Suitable anionic surface-active salts are selected from the group ofsulfonates and sulfates. The like anionic surfactants are well-known inthe detergent art and have found wide application in commercialdetergents. Preferred anionic water-soluble sulfonate or sulfate saltshave in their molecular structure an alkyl radical containing from about8 to about 22 carbon atoms. Examples of such preferred anionicsurfactant salts are the reaction products obtained by sulfating C₈ -C₁₈fatty alcohols derived from e.g. tallow oil, palm oil, palm kernel oiland coconut oil; alkylbenzene sulfonates wherein the alkyl groupcontains from about 9 to about 15 carbon atoms; sodium alkylglycerylether sulfonates; ether sulfates of fatty alcohols derived from tallowand coconut oils; coconut fatty acid monoglyceride sulfates andsulfonates; and water-soluble salts of paraffin sulfonates having fromabout 8 to about 22 carbon atoms in the alkyl chain. Sulfonated olefinsurfactants as more fully described in e.g. U.S. Pat. No. 3,332,880 canalso be used. The neutralizing cation for the anionic syntheticsulfonates and/or sulfates is represented by conventional cations whichare widely used in detergent technology such as sodium, potassium oralkanolammonium.

A suitable anionic synthetic surfactant component herein is representedby the water-soluble salts of an alkylbenzene sulfonic acid, preferablysodium alkylbenzene sulfonates, preferably sodium alkylbenzenesulfonates having from about 10 to 13 carbon atoms in the alkyl group.Another preferred anionic surfactant component herein is sodium alkylsulfates having from about 10 to 15 carbon atoms in the alkyl group.

The nonionic surfactants suitable for use herein include those producedby condensing ethylene oxide with a hydrocarbon having a reactivehydrogen atom, e.g., a hydroxyl, carboxyl, or amido group, in thepresence of an acidic or basic catalyst, and include compounds havingthe general formula RA(CH₂ CH₂ O)_(n) H wherein R represents thehydrophobic moiety, A represents the group carrying the reactivehydrogen atom and n represents the average number of ethylene oxidemoieties. R typically contains from about 8 to 22 carbon atoms They canalso be formed by the condensation of propylene oxide with a lowermolecular weight compound. n usually varies from about 2 to about 24.

A preferred class of nonionic ethoxylates is represented by thecondensation product of a fatty alcohol having from 12 to 15 carbonatoms and from about 4 to 10 moles of ethylene oxide per mole or fattyalcohol. Suitable species of this class of ethoxylates include: thecondensation product of C₁₂ -C₁₅ oxo-alcohols and 3 to 9 moles ofethylene oxide per mole of alcohol; the condensation product or narrowcut C₁₄ -C₁₅ oxo-alcohols and 3 to 9 moles of ethylene oxide per mole offatty(oxo)alcohol; the condensation product of a narrow cut C₁₂ -C₁₃fatty(oxo)alcohol and 6,5 moles of ethylene oxide per mole of fattyalcohol; and the condensation products of a C₁₀ -C₁₄ coconut fattyalcohol with a degree of ethoxylation (moles EO/mole fatty alcohol) inthe range from 4 to 8. The fatty oxo alcohols while mainly linear canhave, depending upon the processing conditions and raw material olefins,a certain degree of branching, particularly short chain such as methylbranching. A degree of branching in the range from 15% to 50% (weight %)is frequently found in commercial oxo alcohols.

Suitable cationic surfactants include quaternary ammonium compounds ofthe formula R₁ R₂ R₃ R₄ N⁺ where R₁,R₂ and R₃ are methyl groups, and R₄is a C₁₂ -C₁₅ alkyl group, or where R₁ is an ethyl or hydroxy ethylgroup, R₂ and R₃ are methyl groups and R₄ is a C₁₂ -C₁₅ alkyl group.

Zwitterionic surfactants include derivatives of aliphatic quaternaryammonium, phosphonium, and sulfonium compounds in which the aliphaticmoiety can be straight or branched chain and wherein one of thealiphatic substituents contains from about 8 to about 24 carbon atomsand another substituent contains, at least, an anionicwater-solubilizing group. Particularly preferred zwitterionic materialsare the ethoxylated ammonium sulfonates and sulfates disclosed in U.S.Pat. Nos. 3,925,262, Laughlin et al., issued Dec. 9, 1975 and 3,929,678,Laughlin et al., issued Dec. 30, 1975.

Semi-polar nonionic surfactants include water-soluble amine oxidescontaining one alkyl or hydroxy alkyl moiety of from about 8 to about 28carbon atoms and two moieties selected from the group consisting ofalkyl groups and hydroxy alkyl groups, containing from 1 to about 3carbon atoms which can optionally be joined into ring structures.

Also suitable are Poly hydroxy fatty acid amide surfactants of theformula ##STR1## wherein R¹ is H, C₁₋₄ hydrocarbyl, 2-hydroxy ethyl,2-hydroxy propyl or a mixture thereof, R₂ is C₅₋₃₁ hydrocarbyl, and Z isa polyhydroxyhydrocarbyl having a linear hydrocarbyl chain with at least3 hydroxyls directly connected to the chain, or an alkoxylatedderivative thereof. Preferably, R₁ is methyl, R₂ is a straight C₁₁₋₁₅alkyl or alkenyl chain or mixtures thereof, and Z is derived from areducing sugar such as glucose, fructose, maltose, lactose, in areductive amination reaction.

Under a given mechanical agitation, heavy sudsing seems to occurparticularly when a surfactant system is used which comprises an anionicsurfactant, particularly a linear alkyl benzene sulfonate, and apolyhydroxy fatty acid amide as hereinbefore described. Accordingly, thepresent invention finds a preferred application in such systems.

The composition according to the present invention can be formulated asa variety of different products, including laundry detergents,dishwashing products and household cleaners. Compositions according tothe present invention may be granular or liquid, aqueous or anhydrous.Depending on the amount of active ingredients, compositions according tothe present invention can be formulated as conventional detergentcompositions or, as an alternative as so-called "concentrated" detergentcompositions. Physical stability issues are more likely to occur inconcentrated liquid detergents, where the total proportion of activeingredient is higher than in a non-concentrated detergent composition.Accordingly, the present invention, which allows to use a lower amountof active ingredients in order to obtain a given suds suppressingperformance finds a preferred application in such concentrateddetergents composition. Preferred compositions herein are concentratedaqueous liquid detergent compositions which comprise less than 30% byweight of water.

The compositions according to the present invention further comprise asuds suppressing system. The suds suppressing system, or suds controlsystem, for use in the compositions according to the present inventioncomprises a mixture of a silicone oil, or mixtures thereof, and a2-alkyl-alcanol, or mixtures thereof.

Suitable silicone oils for use herein have been extensively described inthe art, for instance in U.S. Pat. Nos. 4,798,679, 4,075,118 and EP 150872. Suitable silicone oils for use herein comprise compounds having apolysiloxane backbone, preferably substituted polysiloxane. Alsosuitable for use herein are silicone oils which comprise substitutedpolysiloxanes in mixture with hydrophobic silica and or dispersingagents. Accordingly, the term silicone oil as used herein includesmixtures of polysiloxanes with hydrophobic silica. Suitable siliconeoils for use herein have a viscosity in the range of from 10 to 60000,preferably from 200 to 30000, more preferably from 500 to 12500.Particularly preferred for use herein is a silicone oil comprising apolydimethyl siloxane and hydrophobic silica, with a molecular weight inthe range of from 500 to 12500. Suitable silicone oils for use hereinare commercially available from various companies including RhonePoulenc, Fueller and Dow Corning. The suds suppressing system for useherein comprises from about 0.01% to 2.00% by weight of the totalcomposition of said silicone oil or mixture thereof, preferably from0.05% to 1%, most preferably from 0.1% to 0.5%. Mixtures of siliconeoils can be used in the compositions according to the present invention.

Suitable 2-alky-alcanols for use herein have been described in DE 40 21265. The 2-alkyl-alcanols suitable for use herein consist of a C₆ to C₁₆alkyl chain carrying a terminal hydroxy group, and said alkyl chain issubstituted in the α position by a C₁ to C₁₀ alkyl chain. Preferably,the alkyl chain carrying the hydroxy group is a C₈ to C₁₂ alkyl chain,and the alkyl chain in the α position is a C₂ to C₈ alkyl chain, mostpreferably C₃ to C₆. Preferably all alkyl chains herein are straight. Ithas been found that 2-Butyl-octanol is particularly suitable for useherein. 2-butyl-octanol is commercially available fron Condea under thetrade name ISOFOL 12®. The suds suppressing system for use hereincomprises from 0.05% to 10% by weight of the total composition of said2-alkyl-alcanols, preferably from 1% to 5%, most preferably from 2% to4%. Mixtures of 2-alkyl-alcanols can be used in the compositionsaccording to the present invention. Such mixtures are comprised incommercially available materials, for instance ISALCHEM 123® fromEnichem.

Accordingly, the detergent compositions according to the presentinvention comprise from 0.06% to 12% by weight of the total compositionof said suds suppressing system comprising a silicone oil or mixturesthereof and a 2-alkyl alcanol or mixtures thereof, most preferably from1% to 5%.

The compositions according to the present invention may further comprisethe following optional ingredients.

The compositions according to the present invention may comprise abuilder system. Any conventional builder system is suitable for useherein including polycarboxylates and fatty acids, materials such asethylenediamine tetraacetate, metal ion sequestrants such asaminopolyphosphonates, particularly ethylenediamine tetramethylenephosphonic acid and diethylene triamine pentamethylenephosphonic acid.Though less preferred for obvious environmental reasons, phosphatebuilders can also be used herein.

Suitable polycarboxylates builders for use herein include citric acid,preferably in the form of a water-soluble salt, derivatives of succinicacid of the formula R--CH(COOH)CH₂ (COOH) wherein R is C₁₀₋₂₀ alkyl oralkenyl, preferably C₁₂₋₁₆, or wherein R can be substituted withhydroxyl, sulfo sulfoxyl or sulfone substitutents. Specific examplesinclude lauryl succinate, myristyl succinate, palmityl succinate,2-dodecenylsuccinate, 2-tetradecenyl succinate. Succinate builders arepreferably used in the form of their water-soluble salts, includingsodium, potassium, ammonium and alkanolammonium salts. Other suitablepolycarboxylates are oxodisuccinates and mixtures of tartratemonosuccinic and tartrate disuccinic acid such as described in U.S. Pat.No. 4,663,071

Suitable fatty acid builders for use herein are saturated or unsaturatedC₁₀₋₁₈ fatty acids, as well as the corresponding soaps. Preferredsaturated species have from 12 to 16 carbon atoms in the alkyl chain.The preferred unsaturated fatty acid is oleic acid.

A preferred builder system for use herein consists of a mixture ofcitric acid, fatty acids and succinic acid derivatives described hereinabove. The builder system according to the present invention preferablyrepresents from 5% to 35% by weight of the total composition.

The compositions according to the invention preferably comprise enzymes.Suitable enzymes for use herein are protease, lipases, cellulases andamylases and mixtures thereof. The compositions according to the presentinvention may also comprise an enzyme stabilizing system. Anyconventional enzyme stabilizing system is suitable for use herein, andpreferred enzyme stabilizing systems are based on boric acid orderivatives thereof, 1,2-propanediol, carboxylic acids, and mixturesthereof.

The compositions herein can contain a series of further, optionalingredients. Examples of the like additives include solvents,alkanolamines, pH adjusting agents, opacifiers, agents to improve themachine compatibility in relation to enamel-coated surfaces, perfumes,dyes, color-stabilization systems, bactericides, brighteners, soilrelease agents, softening agents and the like.

EXAMPLES

The compositions according to the present invention will be furtherillustrated by the following examples. The following compositions aremade by mixing the listed ingredients in the listed proportions (weight%).

    ______________________________________                                                        I     II      III     IV                                      ______________________________________                                        C.sub.12 --C.sub.15 Alkyl sulfate                                                               --      19.0    21.0  --                                    C.sub.12 --C.sub.15 Alkyl ethoxylated sulfate                                                   23.0    4.0     4.0   25.0                                  C.sub.12 --C.sub.14 N-methyl glucamide                                                          9.0     9.0     9.0   9.0                                   C.sub.12 --C.sub.14 fatty alcohol ethoxylate                                                    6.0     6.0     6.0   6.0                                   C.sub.12 --C.sub.16 Fatty acid                                                                  9.0     6.8     14.0  14.0                                  citric acid anhydrous                                                                           6.0     4.5     3.5   3.5                                   Diethylene triamine penta methylene                                                             1.0     1.0     2.0   2.0                                   phosphonic acid                                                               Monoethanolamine  13.2    12.7    12.8  11.0                                  Propanediol       12.7    14.5    13.1  10.0                                  Ethanol           1.8     1.8     4.7   5.4                                   Enzymes           2.4     2.4     2.0   2.0                                   Soil release polymer                                                                            0.5     0.5     0.5   0.5                                   Polyvinyl pyrrolidone                                                                           1.0     1.0     --    --                                    Boric acid        2.4     2.4     2.8   2.8                                   2-butyl-Octanol   2.0     2.0     2.0   2.0                                   DC 3421 R (1)     0.3     0.4     0.3   0.4                                   FF 400 R (2)                                                                  Water & Minors    up to 100%                                                  ______________________________________                                         (1) DC 3421 is a silicone oil commercially available from Dow Corning.        (2) is a silicone glycol emulsifier available from Dow Corning.          

All four compositions were physically stable upon storage. CompositionsI and II were tested in washing conditions at 100 mls per wash andcompositions III and IV at 75 mls per wash. No oversudsing was observedwith any of the compositions.

In the compositions above, a suds control system consisting of onlysilicone oil required about 1.3% of silicone oil for an efficientcontrol of sudsing (0.3% to 0.4% in the system of the invention).Similarly, a suds suppressing system consisting only of 2-alky-alcanolrequired about 6% of said 2-alkyl alcanol (2.0% in the system of theinvention).

What is claimed is:
 1. A detergent composition comprising (a) from 5% to60% by weight of the total composition surfactant and (b) from 0.06% to5% by weight of the total composition of a suds suppressing systemcomprising at least one silicone oil and at least one 2-alkyl-alcanolwherein said 2-alkyl-alcanol is present in an amount of 0.05% to 4% byweight of the total composition.
 2. A composition according to claim 1which comprises from 0.01% to 2% by weight of the total composition ofsaid silicone oil.
 3. A composition according to claim 1 which comprisesfrom 20% to 40% by weight of said surfactant system.
 4. A compositionaccording to claim 1 wherein said surfactant comprises a mixture of alinear benzene alkyl sulfonate and a polyhydroxy fatty acid amidesurfactant of the formula (I): ##STR2## wherein R¹ is H, 2-hydroxyethyl, 2-hydroxy propyl or a mixture thereof, R₂ is C₅ -C₃₁ hydrocarbyl,and Z is a polyhydroxyhydrocarbyl having a linear hydrocarbon chain withat least 3 hydroxyls directly connected to the chain, or a polyhydroxyfatty acid amide surfactant of the formula (I) wherein at least onehydroxyl is replaced with an alkoxyl.
 5. A composition according toclaim 1 which comprises from 1% to 5% by weight of said suds suppressingsystem.
 6. A composition according to claim 1 wherein said2-alkyl-alcanol is 2-butyl-octanol.
 7. A composition according to claim1, which is a liquid detergent composition.
 8. A composition accordingto claim 7, which is a concentrated aqueous liquid detergent compositioncomprising less than 30% by weight of the total composition of water. 9.A composition according to claim 1 which comprises 0.1% to 0.5% byweight of the total composition of the at least one silicone oil.
 10. Acomposition according to claim 1 which is a dishwashing composition. 11.A composition according to claim 1 which is a laundry detergent.
 12. Acomposition according to claim 1 which is a household cleaner.
 13. Acomposition according to claim 1, further comprising at least onedetergent ingredient selected from the group consisting of builders,enzymes, enzyme stabilizing systems, solvents, alkanolamines, pHadjusting agents, opacifiers, perfumes, dyes, color-stabilizationsystems, bactericides, brighteners, soil release agents, and softeningagents.